<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>

  <script>
    let obj = {
      name: 'tom',
      age: 18
    }
    let { name: n = 'jerry', age: a = 28 } = obj
    console.log('name', name)
    console.log('n', n)
    console.log('a', a)
    console.log('age', age)
  </script>
</body>

</html>